In industrial products, such as automobiles, home electronics or office automation appliances, metal materials are used for electronic components and micro device components forming those products. These industrial products are used under various environments such as indoor and outdoor, above the ocean, and in factory.
Thus, these metal materials used for industrial products need to endure severe environments including these environments.
Recently, there has been a demand to increase the functionality and density of electronic components and micro device components, and the miniaturization and refinement of these components have proceeded. Accordingly, for the purpose of aiming at protecting the metal materials used for electronic components and micro device components, there has been developed a technique of forming a surface treatment coating on the surface of the metal materials.
For example, there is an embodiment in which an organic surface treatment coating is formed on the metal material surface. Specifically, there is an embodiment in which a surface treatment coating containing an organic constituent as a main ingredient is included, or there is an embodiment in which an organic protective coating made of a sealant is formed. More specifically, there is a method of self-depositing a water-dispersible organic polymer resin on the metal material surface to form a surface treatment coating (Patent Literature 1). Further, there is disclosed a method of forming an organic protective coating made of a sealant containing a specific acrylic resin and inorganic filler (Patent Literature 2).
Further, there is also an embodiment in which an inorganic surface treatment coating is formed on the metal material surface. Specifically, it is disclosed a method of forming an inorganic surface treatment coating on the metal material surface using a surface treatment agent which contains a phosphoric acid-based compound, a fluoro acid containing a predetermined element such as titanium or zirconium, and a silane coupling agent (Patent Literature 3).